Tatiana Ramirez Cunha

A randomised trial on simplified and conventional methods for complete denture fabrication: masticatory performance and ability.

OBJECTIVES To compare a simplified method to a conventional protocol for complete denture fabrication regarding masticatory performance and ability. METHODS A sample was formed by edentulous patients requesting treatment with maxillary and mandibular complete dentures. Participants were randomly divided into two groups: Group S, which received dentures fabricated by a simplified method, and Group C (n=21 each), which received conventionally fabricated dentures. After three months following insertion, masticatory performance was evaluated by a colorimetric assay based on chewing two capsules as test food during twenty and forty cycles. Masticatory ability was assessed by a questionnaire with binary answers and a single question answered by means of a 0-10 scale. A third group (DN) formed by seventeen dentate volunteers served as an external comparator. Groups were compared by statistical tests suitable for data distribution (α=0.05). RESULTS Thirty-nine participants were assessed for three months (twenty from Group C and nineteen from Group S). Groups C and S presented similar masticatory performance which corresponded to approximately 30% of Group DN. Results for masticatory ability showed similarity between S and C, regardless of the assessment method, although an isolate questionnaire item showed more favourable results for the first group. CONCLUSIONS The simplified method for complete denture fabrication is able to restore masticatory function to a level comparable to a conventional protocol, both physiologically and according to patients perceptions. CLINICAL SIGNIFICANCE Although masticatory function is impaired by the loss of natural teeth and dentures can restore only a fraction of such function, patients can benefit from a simplified protocol for complete denture fabrication to the same extent they would by conventional techniques.

Mini vs. Standard Implants for Mandibular Overdentures A Randomized Trial

A mandibular implant-retained overdenture is considered a first-choice treatment for edentulism. However, some aspects limit the use of standard implants—for example, the width of edentulous ridges, chronic diseases, fear, or costs. This randomized trial compared mandibular overdentures retained by 2 or 4 mini-implants with standard implants, considering oral health–related quality of life (OHRQoL), patient satisfaction, and complications such as lost implant. In sum, 120 edentulous men and women (mean age, 59.5 ± 8.5 y) randomly received 4 mini-implants, 2 mini-implants, or 2 standard implants. Participants provided data regarding OHRQoL and satisfaction until 12 mo. Clinical parameters, including implant survival rate, were also recorded. Both 2 and 4 mini-implants led to better OHRQoL, compared with 2 standard implants. Treatment with 4 mini-implants was more satisfying than 2 standard implants, with 2 mini-implants presenting intermediate results. Implant survival rate was 89%, 82%, and 99% for 4 mini-implants, 2 mini-implants, or 2 standard implants, respectively. Overdentures retained by 4 or 2 mini-implants can achieve OHRQoL and satisfaction at least comparable with that of 2 standard implants. However, the survival rate of mini implants is not as high as that of standard implants (ClinicalTrials.gov NCT01411683).

Influence of incorporation of fluoroalkyl methacrylates on roughness and flexural strength of a denture base acrylic resin

Fluorinated denture base acrylic resins can present more stable physical properties when compared with conventional polymers. This study evaluated the incorporation of a fluoroalkyl methacrylate (FMA) mixture in a denture base material and its effect on roughness and flexural strength. A swelling behavior assessment of acrylic resin specimens (n=3, per substance) after 12 h of FMA or methyl methacrylate (MMA) immersion was conducted to determine the solvent properties. Rectangular specimens (n=30) were allocated to three groups, according to the concentration of FMA substituted into the monomer component of a heat-polymerized acrylic resin (Lucitone 550), as follows: 0% (control), 10% and 20% (v/v). Acrylic resin mixed with concentrations of 25% or more did not reach the dough stage and was not viable. The surface roughness and flexural strength of the specimens were tested. Variables were analyzed by ANOVA and Tukeys test (α=0.05). Immersion in FMA produced negligible swelling, and MMA produced obvious swelling and dissolution of the specimens. Surface roughness at concentrations of 0%, 10% and 20% were: 0.25 ± 0.04, 0.24 ± 0.04, 0.22 ± 0.03 μm (F=1.78; p=0.189, not significant). Significant differences were found for flexural strength (F=15.92; p<0.001) and modulus of elasticity (F=7.67; p=0.002), with the following results: 96 ± 6, 82 ± 5, 84 ± 6 MPa, and 2,717 ± 79, 2,558 ± 128, 2574 ± 87 MPa, respectively. The solvent properties of FMA against acrylic resin are weak, which would explain why concentrations over 20% were not viable. Surface changes were not detected after the incorporation of FMA in the denture base acrylic resin tested. The addition of FMA into denture base resin may lower the flexural strength and modulus of elasticity, regardless of the tested concentration.

A randomised trial of a simplified method for complete denture fabrication: patient perception and quality

Complete denture fabrication involves a series of complex technical procedures. Nevertheless, simplified methods may be as effective as conventional ones albeit the lesser use of time and resources, without disadvantage for the patient. This study compared a simplified method for complete denture fabrication to a conventional protocol in terms of oral health-related quality of life (OHRQoL), patient satisfaction and denture quality. Forty-two edentulous patients requesting treatment with complete dentures were randomly allocated into two study groups. Group S received dentures fabricated by a simplified method and Group C received conventionally fabricated dentures. Before interventions and after three and 6 months following insertion, OHRQoL and patient satisfaction were analysed by specific instruments. A prosthodontist assessed denture quality 3 months after delivery. Groups presented no difference for OHRQoL, denture quality and general satisfaction. Differences regarding patient satisfaction with some aspects of the dentures were found after 3 months (S > C), but were insignificant at 6 months. It was concluded that the simplified method is able to produce dentures of a quality comparable to those produced by the conventional method, influencing OHRQoL and patient satisfaction similarly.

A Randomized Trial on Simplified and Conventional Methods for Complete Denture Fabrication: Cost Analysis

PURPOSE This study aimed to quantify the costs of complete denture fabrication by a simplified method compared with a conventional protocol. MATERIALS AND METHODS A sample of edentulous patients needing conventional maxillary and mandibular complete dentures was randomly divided into group S, which received dentures fabricated by a simplified method, and group C, which received conventionally fabricated dentures. We calculated direct and indirect costs for each participant including unscheduled procedures. This study assessed 19 and 20 participants allocated into groups S and C, respectively, and comparisons between groups were conducted by the Mann-Whitney and Students t-test (α = 0.05). RESULTS Complete denture fabrication demanded median time periods of 173.2 and 284.5 minutes from the operator for groups S and C respectively, and 46.6 and 61.7 minutes from the dental assistant (significant differences, p < 0.05). There was no difference between groups regarding postinsertion adjustments. Group S showed lower values for costs with materials and time spent by patients than group C during the fabrication stage, but not during adjustments. CONCLUSIONS The median direct cost of complete denture treatment was 34.9% lower for the simplified method. It can be concluded that the simplified method is less costly for patients and the health system when compared with a conventional protocol for the rehabilitation of edentulous patients.

Short-term post-operative pain and discomfort following insertion of mini-implants for retaining mandibular overdentures: a randomized controlled trial.

The retention of removable dentures by mini-implants is a relatively recent treatment modality and may lead to minimal post-operative trauma. This study compared post-operative pain and discomfort following the insertion of mini-implants (two or four) or two standard-size implants for the retention of mandibular overdentures. One hundred and twenty edentulous participants (mean age 59.5 ± 8.5 years) were randomly allocated into three groups according to received treatment: (GI) four mini-implants, (GII) two mini-implants or (GIII) two standard implants. Seven days after implant insertion, patients answered questions (100-mm VAS) relating to pain, swelling, and discomfort with chewing, speech and hygiene, considering their experiences during the 1st and 6th day. Groups were compared by two-way anova (α = 0.05). All participants (GI: 38; GII: 42; GIII: 40) were analysed after 7 days. At the 6th day, GI felt significantly higher pain than GII and GIII. GI also reported more difficulty in performing oral hygiene practices than GIII during the 1st day. There was no significant difference between groups for the other questions and periods. No participant suffered unexpected side effects. The use of four mini-implants induces more intense post-operative pain at the 6th day than the insertion of two mini- or conventional fixtures, as well as more difficult oral hygiene on the 1st day. Clinicaltrials.gov, NCT01411683; FAPESP, 2011/00688-7 and 2011/23347-0.

The Effect of Polymerization Cycles on Color Stability of Microwave-Processed Denture Base Resin

PURPOSE This study evaluated the effect of different microwave polymerization cycles on the color changes of a microwave-processed denture base resin after accelerated aging and immersion in beverages. MATERIALS AND METHODS Specimens of light pink acrylic resin were divided into three groups according to polymerization cycle: (A) 500 W for 3 minutes, (B) 90 W for 13 minutes + 500 W for 90 seconds, and (C) 320 W for 3 minutes + 0 W for 4 minutes + 720 W for 3 minutes. Control groups were a heat-processed acrylic resin (T) and a chemically activated denture repair resin (Q). Eight specimens per group were aged in an artificial aging chamber and evaluated at 20, 192, and 384 hours. Another series of 40 specimens per group were immersed in water, coffee, tea, cola, or red wine and evaluated at 1, 12, and 36 days. Color was measured by a spectrophotometer before and after aging or immersion. Color changes (DeltaE) were analyzed by ANOVA/Bonferroni t-test (alpha = 0.05). RESULTS Mean DeltaE (+/- SD) after 384 hours of accelerated aging were (A) 2.51 +/- 0.50; (B) 3.16 +/- 1.09; (C) 2.89 +/- 1.06; (T) 2.64 +/- 0.34; and (Q) 9.03 +/- 0.40. Group Q had a significantly higher DeltaE than the other groups. Color changes of immersed specimens were significantly influenced by solutions and time, but the five groups showed similar values. Mean DeltaE at 36 days were (water) 1.4 +/- 0.8; (coffee) 1.3 +/- 0.6; (tea) 1.7 +/- 0.5; (cola) 1.4 +/- 0.7; and (red wine) 10.2 +/- 2.7. Results were similar among the five test groups. CONCLUSIONS Color changes of the microwave-polymerized denture base resin tested were not affected by different polymerization cycles after accelerated aging or immersion in beverages. These changes were similar to the conventional heat-polymerized acrylic resin test, but lower than the repair resin after accelerated aging.

Development of a Low-Cost Insulin Infusion Pump: Lessons Learned from an Industry Case

In the last 30 years there have been great advances in technology for diabetes treatment, which facilitated the management of the disease and its complications. Among the advances we can mention the development of insulin infusion pump. However, diabetes treatment using the insulin pump still remains expansive in Brazil, especially because the device and its accessories are imported. The aim of this paper is to report a prototype development of a low-cost insulin infusion pump aimed to benefit Brazilian people suffering with Diabetes Mellitus type 1. The prototype development is a result from a cooperation between Brazilian academy and industry. We comment the development of such a prototype and the lessons learned obtained from it.

Comparing a tablet computer and paper forms for assessing patient-reported outcomes in edentulous patients

PURPOSE The aim of this study was to determine whether two methods of documentation, print and electronic forms, for the assessment of patient-reported outcomes (PRO) in complete denture wearers provide comparable results. The study also quantified the time needed for filling the forms by each method. MATERIALS AND METHODS Thirty participants enrolled in a university clinic answered two forms (a questionnaire for denture satisfaction and OHIP-EDENT). They provided answers with two application methods in a random order, with a one-month interval between them: (1) electronic forms on a tablet computer; and (2) print forms. The methods were compared in terms of mean results, correlation/agreement, internal consistency, and spent time. RESULTS Mean results for both methods were similar for each denture satisfaction item (100-mm VAS) and OHIP-EDENT summary score. Both questionnaires presented good internal consistency regardless of the application method (Cronbachs α=0.86 or higher). Correlation and agreement between the methods regarding specific items was at least moderate for the majority of cases. Mean time for the electronic and print forms were 9.2 and 8.5 minutes, respectively (paired t test, P=.06, non-significant). CONCLUSION The electronic method is comparable to print forms for the assessment of important PRO of prosthetic treatment for edentulism, considering the results and time needed. Findings suggest the viability of replacing print forms with a tablet for applying the tested inventories in clinical trials.

Mini-Implants for Mandibular Overdentures: Cost-Effectiveness Analysis alongside a Randomized Trial

Mandibular overdentures retained by 2 conventional implants have been considered the standard of care for complete edentulism, according to the McGill and York consensuses. However, many patients refuse this treatment modality due to the associated costs and postsurgical discomfort. Mini-implants have the chance to overcome these limitations due to their potentially lower costs and a relatively uncomplicated surgical technique. This study compared treatment costs and incremental cost-effectiveness following the insertion of mini-implants (2 or 4) or 2 standard-size implants for the retention of mandibular overdentures, by means of a randomized clinical trial. In total, 120 edentulous participants (mean age 59.5 ± 8.5 y) were randomly allocated into 3 groups according to treatment received: 4 mini-implants (group 1), 2 mini-implants (group 2), or 2 standard implants (group 3). Treatment costs and outcomes (Oral Health Impact Profile for Edentulous [OHIP-EDENT] and satisfaction with the dentures) were evaluated after 6 mo. Incremental cost-effectiveness ratios (ICERs) were calculated for each intervention in terms of cost per 1-point change in patient outcomes. A 1-way sensitivity analysis was performed considering a 95% confidence interval variation in cost and outcome parameters, represented in tornado diagrams. Overall treatment cost was the lowest for group 2 (average cost: US